The most brutal rematches are born through intense boxing rivalries sometimes stoked by hatred, a competitive nature or a general push by the people.
Boxing thrives off rivalries. When the fans and media gawk in near-equal astonishment at two boxers' accomplishments near or in the same division, there grows a desire for them to meet in the ring.
Once this desire is fulfilled, the fans want more if the first match was entertaining enough. Sometimes rematches become more thrilling than their predecessors.
The results can be surprising with shockingly early finishes, or the results could repeat the first match with more of the same with just that much more sustained violent action.
Either way, a brutal rematch delivers upon the violent promise of the first match and then some. Here are boxing's most brutal rematches.